Antenna-switching relay



l A. HADDOCK ANTENNA swITcHING RELAY 'Filed June 22, 1922 2 Sheets-Sheet 1 f7? s '/9 'Y /f /5 "'23 a 2f Z Q7 MW Nov. l, 1927.

. 1,647,290 A. HADDocK ANTENNA SWITCHING RELAY l Filed'Junezz, i922 2 sheets-sheet2 Patented Nov.` 1, 1927.

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ARTHUR HADDOCK,OF EAST ORANGE, NEVI JERSEY, 'ASSGNOR TO WESTERN ZELEIC- TRIC- ('JOIVIEANY,l INCORPORATED, NEW- YORK, N. Y., A COREORATIION OF NEW YORK.

Application filed .Tune 22,

l The invention relates to antenna switching relays and more Aparticularly 'to adevice of this typefor use in high power radio sysi VThe present invention is directed lto an arrangement inclu-ding a transmit-receive relay having its contacts ettectively insulated kfrom thel supporting frame and provided with ymeans for controlling` 'the voltage of the high frequency source at the instant whenI the connection between the transmitting circuit'and antenna is made and broken.

In' accordance-with this invention the switching mechanism comprises a single throw relay switch having a plurality of separate contacts each mounted on a long insulating column. The Vcolumns are arranged in pairs and .secured to a supportingA base in spaced relationV to provide a long break path between the pairs of contacts,v as well as between the contacts of each pair. A pivoted yoke having correspondingly long insulating arms carrying a contact element normally spring held in engagement with one pair of iixed contacts and adapted to be thrown over into engagement with the second Ypair of fixed contacts by an electromagnet, and pairs of auxiliary contacts adapted to be actuated by the movement of the pivoted yoke. One pair of contacts .serve to 1 reduce the voltage of the high frequency source at the proper instant and the other'` pair operate to control the value of the hold ing currentsupplied to the magnet coils.

The preceding statement is given with the object of .describing in a general way one practical form of switching mechanism utilizing` the principles of the present invention, but is not to be interpreted as delining its scope. binations believed to be characteristic of TheV novel features and coin- Y ANTENNA-suriname RELAY.

1922. serial No. 579,053.

this invention will. be pointed out with par-i ticularity in the attached claims. L

One object of this invention is to provide a simple switching arrangement adapted for use in 'a high vpower radio system 'employing asingle antenna for transmitting and receiving. l y l l Another object is the provision of aftrans-v mit-receive relay for a highfpower radio.

systemk having its contacts effectively insu? lated from ground and provided with means for controlling the voltagev impressed` upon` these contacts at the instant vwhen the 'transmitting circuit is connectedjto'and disconvV`V nected from the antenna.

.Theinvenaonieeif how/eier, with fuffhe'rf Y objects and advantages thereof, will best be understood by reference to thevfollowingdei scription taken in conjunction withv 4threat-ltached drawings in whichFig. 1 shows a sectional view of a relay switch designed iiiV i accordance with this invention, the section being taken on the broken line ie-a of Fig. 2; Fig. 2 shows a 'plan view of the relay; Fig 3 is a diagrammatic representation of a radio system'including the switching mech anism of the present invention; Fig. Llisa digraininatic illustrationv of a" lpart ofthe radio circuit using a relay rhaving lits auxiliary contacts arranged in a slightly differ# ent mannerand Fig. 5 is a .sectional view of 'al portion of the relay structure', j showing an alternate arrangement of the auxiliary contacts for controlling the'high frequency source. v f i As shown in Fig. l the base plate 1 vof the relay has secured thereto four relatively l long tubular insulators 2, a supporting frame 3, upon which a magnete and a yoke -5 are mounted, a resistance element 6 and a pair of lugs 7 to which theauxiliarysyvitches are secured, these auxiliary switches each con--v sist of a pair of spring contacts 8 which are insulated from eachother by aninsulating strip 9 and are also insulated from the lugs 7 V The base plate 1 is provided with four widely spaced reinforcing bosses 10 arranged in pairs which are drilled to provide interior shoulders 1l, the insulators 2 being held in position upon the plate 1 with their low-er ends in engagement with Vthe shoul-y ders 11 by screws 12 which project through the bosses 10 and engage interiorly threaded poi-tions 13 of the insulators 2. n

' enl Mounted upon the upper end of each of the insulators 2 is a terminal lug 14 of conductive material to which is secured a switch contact 15. These terminal lugs are held in fixed position relatively to the insulators by pins 1G. This arrangement constitutes an important feature of the relay construction since by loosening` the screws 12 the insulators 2 may be separately adjusted to eect proper alignment of the contacts 15 rela-.

tively to one another and a cooperating movableV Contact to be hereinafter referred to.

The electromagnet 4 consists of a pair of coils secured to an upper transverse arm of the rectangular frame 3. The coils are provided with cooperating` cores which are connected to the yoke 5.v This yoke is pivotally connected to the frame 3 by means of a pair of pins 17.

Secured to the yoke 5 are long insulating arms 18 between the outer ends of which eX- tends a long contact element 19 which is nor- Inally held in engagement with the left hand pair'of contacts 15 by the spring 20, one end of which is connected to the lug 21 carried by the yoke, while the other end is secured to an arm 22 projecting trom the magnet frame by an adjustable connection 23, whereby the tension of the spring may be regulated. Upon energization ofthe magnet 4, the yoke 5 will be rotated abouty the pins 17 and the Contact element- 19 will engage the pair of right-hand contacts 15.

The contacts are of resilient conductive material, substantially S-shaped, and areso positioned that the movable contact 19 wipes over an Aappreciable length thereof before comingto rest in engagement with their upwardly curved rear portions. Thus, the surfaces of these contacts are always kept bright whereby a good contact is assured. -Moreover, because of their resiliency these contacts move in the direction of travel of the contact 19 and operate to absorb the shock due to the inertia of the movable element whereby chatter is prevented.

Y As shown in F ig. 2 the yoke 5 is provided with insulating pins 24 adapted to engage `one of the contacts 8 of each of the auxiliary switches.

The pins 24 are so positioned relatively to the movable contact 8 that in the normal position of the contact 19, the upper auxiliary switch will be opened, while the lower auxiliary switch will be closed and in the other extreme position of the contact 19, the upper auxiliary switch will 'be closed and the lower auxiliary switch will be opened.

The antenna will be connected to the upper left-hand terminal lug` 14 which in turn may be connected by a strap to the upper righthand terminal lug 14, the lower left-hand lug- 14 being connected to the receiving apparatus, while the lower right-hand lug 14 is connected to the transmitting apparatus.

It will be apparent that with the movable switch element in the position shown in Fig. 1 the receiving apparatus will be connected to the antenna, the upper `auxiliary switch will be opened and the lower auxiliary switch will be closed.

The upper auxiliary contacts 8 are adapted to control the oscillator so that when the main relay contact 19 is in engagement with the left-hand contacts 15substantially no oscillating current is generated, while the lower auxiliarycontacts serve to c omplete the energizing` circuit for the coils of the magnet 4.

vWhen the relay Contact 19 is thrown into engagement with the right-hand contacts 15, the transmitting` apparatus willbe connected to the antenna, the upper auxiliary contacts will be closed to short-circuit a resistance associated with the. high potential source including in the transmitting circuit, whereby oscillating current will be generated and supplied to the antenna.

lin order to avoid arcing at the main relay contacts when the transmitting apparatus is connected to the antenna, the upper auX- iliary contacts 8 should not be closed until after the movable Contact 19 has come into engagement with the right hand stationary contacts 15whereas upon the reverse movement of the movable switch arm the contact 19, carried thereby, should remain in engagement with the right-hand contacts 15 until the circuit through the upper auxiliary contacts 8 has been opened.

Referring now to Fig. 3 there is shown a radio signal station comprising an antenna 30, a receiving circuit 31, a transmitting circuit 82 and a transmit-receive relay 33 of the type described above. In normal posiion the relay connects the antenna to the receiving apparatus through the upper contacts 15 and movable contact 19. j

For the purpose of disclosing the operation of this invention, it is herein shown as appliedy to a radio system employing a transmitting apparatus similar to that disclosed in the proceedings of the linstitute of Radio Engineers for December, 1921, with special references to thel circuit diagrammatically shown in Fig. 11 on page 482. As described with reference to the above mentioned figure speech frequency current is applied to an amplifier, the output of which is impressed on the grid circuits of two parallel modulator tubes, the output voltage of these tubes being` impressed upon the plate circuits of two oscillator tubes by a low frequency choke coil common to the modulator and oscillator plate circuits. By this arrangement modulation of the oscillator plate potential is effected and results in speech frequency variations of the amplitude of the antenna current. l

The present intention being directed solely to an arrangement for controlling the'operation of. thevoscillator, the modulator is not illustrated 'in'Fim 3. However, it is to be understood' that trie/common output circuit ofy the rmodulator tubes is connected at to the `positive terminal of the supply source 36,y

adapted to'supply direct current to the plate circuits'of the oscillating and modulatingl coil y Space current for the oscillating tubes 37 flows through the high frequency choke coil tubes through the 'low 'frequency choke f 3,9, the inductance coil of the oscillator output circuit 34 to the plate elements of the tubes,

' tacts are closed.

across the space within the tubeto the catho-des thereof, and thence through the series connected resistances 40 and 41 to thel As therein shown the movable contact 19V of the relay switch is normally lheld in engagement with the upper pair of contacts 15, the upper pair of auxiliary contacts are opened and the lower pairfof auxiliary con- As described abo-ve the receiving apparatus 31 is therefore connected to the antenna 30, and the resistance 40 and the shunt path 42' are included in both circuits of the oscillating tubes. `The'drop of potential across the resistance 40is impressed upon the grid elementsl of the tubes 37 andis such that substantiallyv no oscillaty ing current is generated.1

W'hen it is desired to transmit a message from a station of this character, the switch 44 is closed to energize the relay 45, the circuit 46 being thereby completed to supply A current from the source 47 to the coils of the magnet 4. Upon energization of the magnet coils, the yoke 5, as described above with reference to Fig. 2, is actuated to disconnect the contact 19 from the left-hand contacts 15, herein represented as the upper pair of contacts, and to cause element 19 to engage the righthand main contacts, herein represented as the lower pair of contacts 15, the upper auxiliary contacts 8 are. closed,

while the lower pair of auxiliary contactsv are opened. The transmitting apparatus is therefore connected to the antenna, the'resistance 4() and the shunt path 42 are shortcrcuited by the upper auxiliaryT contacts 8 and, as a consequence, the potential impressed uponthe grids of the tubes 37 is reduced so that high frequency oscillating current is thereby generated and suppliedy to the antenna. At the same time, the lower auxiliary4 contacts 8 are opened and the resistance 48 is included in the energizing circuit 46, whereby the current supplied vto `the coils of the magnet 4 is' reduced from the high am-l perage initially used to actuate the relay imk to a value which, while suiiici'ent tomaintain i i the relay contacts iii-transmit position, may

be safely supplied to the magnet coils with i out causing them to become overheated.

A transmitting apparatus of this character adapted to supply 500 watts to the antenna at about 5,000 volts and controlled in the manner described above has been tested.' This apparatus comprised tubes having internal impedances of 2,000 ohms, direct current at about 1,600 volts.beingimpressed,

upon their plates throughv a resistance of.V 2,000 ohms shunted'by a path including 200 ohms and a capacity of .5 microfarads, the resistance and path being controlled by the upperauxiliary contacts 8 to determine,l the potentials' impressed `upon-the gridsiof 'the .described above. With an apparatus of'this* type the relay.- was foundfto operate sub stantially without arcing when actuated to connect this apparatus to and disconnect it from the antenna.A Y i r liy substituting the arrangement diagram- 'oscillating tures `at the proper instants,"a5f

matically shown in Fig. 4 forthat portion p of the circuit to the right of thesection-line Be-B in Fig. 3, a radio system which is especially adapted forbroadcas'ting is provided. Tlie conductor y49 is connected to the upper terminal of the couplingl coil 43, the conductor 50 leads to the commoncon'- necting point of the'resistance 41,"withitheV alternatingl path 42 kand resistance40vand the conductors 51 serve to completefthe en?` ergizing circuit 46 forv the ,coilsof the magnet 4. 1 With the control switch y44 in open position, as shown in Fig. 3, the movable relay contact 19 is held in engagement with the upper pair of contacts 15 which are respectively connected to the antennay 30 and the conductor 49 and both pair of auxiliary contacts 8 are closed.v The transmission appa-y ratus is therefore connected to the antenna and resistance '40 and AC path 42 are shortcircuited and highl frequency current generated by the Voscillating tubes 37 and associate circuits is supplied to the antenna.

To listenin the operator closes the control'switch 44, the coils of the magnet 4 will be energized and the movable Contact 19 will be actuated to disconnect the antenna/from the transmitting apparatus and connect it to the receiving apparatus. When this occurs both pairs of auxiliary contacts will be opened, the resistance 40 willA be included in the space current pathv of the tubes 37 to substantially preventthe generation of oscillating current, and the-resistance 48 will be included in the energizing circuit ot the Vmagnet coils which, as described above, reduces the current flowing through Vthis circuit so that overheating ot the inagnet coils will not occur.

When used for broadcasting the following changes will be necessary. rllhe transmission apparatus will be connected to the lower lett-hand terminal lug 14 of the relay as shown in Fig. 2, while the receiving apparatus will be connected to the lower righthand terminal lug, the upper auxiliary contacts will be reversed so that they are normally closed, and the cooperating pins 24 will be closely spaced relatively to the movable contact et this pair. As described above, the position ot the auxiliary contacts for controllingv the high Yli'reduency source is such that they are open circuited, to include resistance 40 and shunt path 42 in both circuits of the tubes 37, before the contact 19 moves ont of engagem-L- t with the righthand pair ot contacts 15 and are held in open circuit position until after the element 19 again engages this pair ot contacts upon its return to normal position Fig. 5 illustrates the arrangement of the auxiliary contacts 8 for controlling the high voltage source when the relay is used in a broadcasting station and also indicates the position oic the actuating pin 24 relatively to the movable contact ot the auxiliary pair. Moreover, it serves to represent the arrange ment of the lower auxiliary contacts 8 oi' Fig. 2, though in this case the position ot the insulating pins 24 relatively to the movable, contact of the auxiliary pair will be such that these contacts will not be opened to include the resistance 48 in the energizing circuit 46 until the switch arms 18 have about come to rest in the transmit position. With the arrangement `iust described the movable relay contact is spring held in the transmitting position and the coils ot the magnet 4 are only energized during listen ing-in periods, which are relatively brief. llfhen the arrangement shown in Fig. $3 is used for broadcasting, current must be-supplied almost continuously to the magnet coils with the result that energy is wasted, and the danger of overheating the magnet coils is increased. Hence, for broadcasting, the circuit of Fig. 4 not only eii'ects a material saving in the energy used to control the relay, but the liability oi overheating the magnet coils is reduced to a minimum.

Frein the preceding description. it will be apparent that the present invention pro; vides a simple rugged relay structure having its contact effectivelyv insulated to withstand high voltages. Because ot the use ot the auxiliary contacts, associated with its movable element for controlling the high frequency source, this device is especially adapted for use in a. high power radio staneat/eee tion employing a single antenna for both transmitting and receiving. Gbviously, with this arrangement, dashing across between the relay contacts is prevented, a good contact is always assured, and the inertia et the movable element is eiiectively absorbed to prevent chatter. Again, the voltage of the high tension source is substantially nil' at the mo- Hieiit when the transmitting circuit is connected to and disconnected troni the antenna, whereby destructive arcing at the niain relay contacts is avoided.

lialliile a spe iiic arrangement has been described with the object oi' completely and clearly disclosing the principles oi the invention, it is to be understood that this invention is not limited to the specific details herein shown and described, but only by the scope ci the attached claims.

llhat is claimed is: v

1. An antenna switch relay comprising a base, a plurality oi' relatively long insulators connected to and Iextending an appreciable extent trom said base, said insulators being arranged in pairs, a contact mounted on each ot said insulators, said contacts being arranged in pairs, a pivoted yolre provided with relatively long insulating arins,a single contact element carried by said arms Yfor bridging a pair of said contacts in either extreme position ofthe yoke, a spring tor normally holding said single contact element in engagement with one pair oi said First mentioned contacts, and n electromagnet, associated with said yoke, t ,pted when energized to bring said con tact element into engagement with said other pair of lirst mentioned contacts.

2. An antenna switching relay comprising a base, a plurality oit long insulators secured to and extending a substantial extent from said base, said insulators being arranged in pairs, a contact carried by each of said insulators, said contacts being arranged in pairs, the insulators being spaced apart to provide a long break path between the pairs ot contacts secured thereto, a pivoted yoke provided with relatively long iii,-

siilating arms, a single contact element carried by said arms tor bridging a pair of said contacts in either extreme position ot' said yoke, a spring 'for normally holding said contact element in eiigagernent with one oi said pairs olf lirst mentioned contacts. and an electroii'iagiiet, associaled with said yoke, adapted when energized to bring said contact element into engagement with said other pair ot tirst mentioned contacts.

3. An antenna switching relay compri?- ing a base, a plurality oiu relatively long insulators secured to and extending an appreciable extent trom said base, a contact carried by each insulator, said contacts being arranged iii pairs and said insulators being relatively widely spaced apart in two gli ico

' and also between the contacts ot eachL pair,

a lpivoted yoke provided with relatively long insulating arms, a single contact element carried by sa-id'arms for bridging a pair ot said contacts in either extreme position oi' said yoke, a spring 'for normally holding said contact element in engagement with one of said pairs of tirstmentioned contacts, and an electromagnet, associated with said yoke, adapted when energized to bring said contact element into engagement with lsaid other pair ot" first mentioned contacts.

4. In a radio signal system a transmitting circuit having a source of high frequency oscillating current included therein, a receiving circuit, an antenna switching relay adapted to connect either said transmitting circuit or said receiving circuit to vsaid antenna, said relay comprising a base, a plurality of relatively long insulators connected to said base. and arranged in pairs, a main contact mounted on each of said insulators, said main contacts being arranged in pairs, a pivoted yoke provided with relatively long insulating arms, a single contact element carried by said arms, a spring 'for normally holding said contact element in engagement with one of said pairs of iirst mentioned contacts, and an electromagnet, associated with said yoke, adapted when,` energized to bring said Contact element into engagement with said other pair of lirst mentioned contacts, an energizing circuit for said electromagnet, a pair of auxiliary contacts operated lby said yoke for controlling said supply o1c high frequency oscillating' current when said contact element is in engagement with one pair of said main contacts, and a second pair of auxiliary contacts operated by said yoke and included in said electromagnet energizing circuit, said first mentioned auxiliary contacts being closed after the bridging of the first pair ot main contacts by` the contact element and opened prior to the disconnecting of the first pair of main contacts from the cont-act element so that no high holding said Contact element in engagementA with said other pair of main relay contacts.

5. An antenna switching relay Vcomprising a base having a plurality of pairs ot openings provided with interior shoulders, ay plurality of insulators having one end lportion interiorly threaded, the interiorly threaded portion of each insulator projecting into an opening 1n the base, a screw projecting through each of the openings inthe base adapted to engage the interiorly threaded portions of the insulators to thereby hold them 1n engagement with the shouldered portion of the opening, a terminal lug rigidly secured to the opposite end of cach insulator, a spring contact carried by each of said lugs, and a movable contact adapted to be controlled to cause it to engage either pair of spring contacts. Y

6. An antenna, a receiving apparatus, a

transmitting apparatus, an antenna switch for connecting the antenna either tothe transmitting apparatus or to the receiving apparatus, resilient means normallyfoperating to connect the antenna to the transmitting apparatus, an electromagnet remotely controlled t'or operating said switch to conneet the antenna to the receiving apparatus, `an auxiliary switch for controlling said transmitting apparatus, said auxiliary switch being in closed position to energize the transmitting apparatus, and means for closing the auxiliary switch after operating the antenna switch to connect the antenna to the transmitting apparatus and for opening the auxiliary switch prior to the opening of the antenna switch to disconnect the antenna from the transmitting apparatus, whereby flashing over at the'antenna switch is prevented. i

'zo i 7. An antenna, a receiving apparatus, a

transmitting apparatus, an antenna switch comprising two pair ot contacts and a. movable contact element, said movable contact element engaging one pair ot said contacts to connect the transmitting .apparatus to vthe antenna land engaging the other pair of contacts to connect the receiving apparatus to the antenna, resilient means normally-operating the contact element to conneet the transmitting apparatus to the Y.

antenna, an electromagnet for moving the contact element to connect the receiving apparatus to the antenna, remote controlmeans for energizing said electromagnet, an auxiliary switch for controlling said transmitting apparatus, said auxiliary switch being in vclosed position to energize the transmitting apparatus, and means for closing the auxiliary switch after the contact element engages tbe contacts to connect the transmitting apparatus to the antenna and for opening the auxiliary switch prior to separation of the contact element from the contacts to separate the transmitting apparatus from the antenna, whereby flashing over between the contacts is prevented.

In witness whereof,- I hereunto subscribe my name this 20th day of J une A. D., 1922.v

ARTHUR HADDOCK. 

